1. Field of the Invention
The present invention relates to a mounting structure of a head mounted device onto a head.
2. Related Background Art
FIG. 13 and FIG. 14 each show a mounting mechanism provided to a conventional head mounted display (hereinafter referred to as HMD) and the like.
The conventional HMD is provided with a front head pressing pad 22 abutting onto a front head of a wearing person, a back head pressing pad 24 abutting onto a back head, a pad mounting member 25 for retaining the back head pressing pad 24, and a frame 23 for connecting the pad mounting member 25 and the front head pressing pad 22.
Here, it is possible to mount the HMD onto the head by adjusting the distance between the front head pressing pad 22 and the back head pressing pad 24 by using a length adjusting mechanism 26. Besides, the wearing person of the HMD can observe an image displayed on a display unit 21.
In addition, in the HMD, as shown in FIG. 14, by pressing a back head pressing portion 34 onto the back head of the wearing person by using a bias force of a spring 35, a position of a display unit 31 is prevented from being lowered by its weight M (see, for example, Japanese Patent Application Laid-Open No. H11-298826). Besides, in the HMD, a front head pressing portion 33 is pressed onto the front head of the wearing person by the bias force of a spring 32.
In the conventional mounting mechanism, it is possible to mount the HMD while confirming a status (direction and the like) of the front head pressing portion because the front head pressing portion is located on the front head side. However, it is not possible to confirm a status (direction and the like) of the back head pressing portion in mounting the HMD because the back head pressing portion is located on the back head side.
Especially, in a case where the frame connecting the front head pressing portion and the back head pressing portion is made of a relatively soft material with flexibility, if the back head pressing portion is hooked on the back head when mounting the HMD, a back head pressing portion 41 is rotated in a direction indicated by an arrow I as shown in FIG. 15. As a result, a connecting portion 43 which is connected to a frame 42 and supports the back head pressing portion 41 is rotated in a direction indicated by an arrow H in FIG. 15.
In this case, if the wearing person tries wearing the HMD by force without recognizing that the back head pressing portion 41 is rotated, the HMD is mounted on a head with the back head pressing portion 41 being reversely rotated.
On the other hand, if the HMD as disclosed in Japanese Patent Laid-Open No. H11-298826 is not mounted on a head, the back head pressing portion 34 is rotated by a predetermined amount in a direction indicated by an arrow T2 due to the bias force of the spring 35, as compared to a state shown in FIG. 14.
When mounting the HMD in the state like this, it is necessary to rotate the back head pressing portion 34 in a direction opposite to the direction indicated by the arrow T2 against the bias force of the spring 35 so as to prevent the back head pressing portion 34 from being hooked on the head of the wearing person. Alternatively, it is necessary to mount the HMD in a state where the distance between the front head pressing portion 33 and the back head pressing portion 34 is made sufficiently longer than the width of the head.
As described above, in the case of the conventional HMD, the wearing person has to perform a mounting operation while being aware of the status of the back head pressing portion, which gives inconvenience to the wearing person.